This is a clinical trial of UDCA and MTX in the treatment of patients with PBC. UDCA appears to protect against the cytotoxic effects of endogenous bile acids that accumulate as a result of bile duct destruction. BMT is being shown to improve liver tests, symptoms and liver histology in a small number of pre-cirrhotic patients with PBC. The mechanism of action is unknown but is felt to be related to anti-inflammatory immunosuppressive effects of MTX.